<template>
	<view class="previewImage" :style="{ 'background-color': 'rgba(0,0,0,' + opacity + ')' }" v-if="show" @tap="close"
		@touchmove.stop.prevent>
		<swiper class="swiper" :current="index" @change="swiperChange" :disable-touch="swiper" :circular="circular">
			<swiper-item v-for="(img, i) in imgs" :key="'swiper-item-'+i" :id="'swiper-item-'+i">
				<movable-area class="marea" scale-area>
					<movable-view :id="'movable-view-'+i" :key="'movable-view-'+i" class="mview" direction="all"
						:out-of-bounds="false" :inertia="true" damping="90" friction="2" scale="true" scale-min="1"
						scale-max="4" :scale-value="scale" @scale="onScale" @change="movableChange">
						<image :id="'image-'+i" :key="'movable-view'+i" class="image" :src="img"
							:style="{ transform: 'rotateZ(' + deg + 'deg)' }" :data-index="i" :data-src="img"
							mode="widthFix" @touchmove="handletouchmove" @touchstart="handletouchstart"
							@touchend="handletouchend" />
					</movable-view>
				</movable-area>
			</swiper-item>
		</swiper>
		<view class="page" v-if="imgs.length > 0">
			<text class="text">{{ index + 1 }} / {{ imgs.length }}</text>
		</view>
		<view class="save edit" v-if="editBtn" @click.stop.prevent="edit(index)"><text class="text">替换</text></view>
		<view class="save del" v-if="delBtn" @click.stop.prevent="del(index)"><text class="text">删除</text></view>
		<view class="save" v-if="saveBtn" @click.stop.prevent="save"><text class="text">保存</text></view>
		<view class="rotate" v-if="rotateBtn" @click.stop.prevent="rotate"><text class="text">旋转</text></view>
		<view class="desc" v-if="descs.length > 0 && descs.length == imgs.length && descs[index].length > 0">
			{{ descs[index] }}
		</view>
	</view>
</template>

<script>
	export default {
		name: 'ksj-previewImage', //插件名称
		props: {
			imgs: {
				//图片列表
				type: Array,
				required: true,
				default: () => {
					return [];
				}
			},
			descs: {
				//描述列表
				type: Array,
				required: false,
				default: () => {
					return [];
				}
			},
			//透明度,0到1之间。
			opacity: {
				type: Number,
				default: 0.8
			},
			//保存按键
			saveBtn: {
				type: Boolean,
				default: true
			},
			//旋转按键
			rotateBtn: {
				type: Boolean,
				default: true
			},
			//编辑按键
			editBtn: {
				type: Boolean,
				default: false
			},
			//删除按键
			delBtn: {
				type: Boolean,
				default: false
			},
			//循环预览
			circular: {
				type: Boolean,
				default: false
			}
		},
		data() {
			return {
				swiper: false, //是否禁用
				show: false, //显示状态
				index: 0, //当前页
				deg: 0, //旋转角度
				time: 0, //定时器
				interval: 1000, //长按事件
				scale: 1 //缩放比例
			};
		},
		methods: {
			//比例变化
			onScale(e) {

			},
			// 强制刷新页面
			forceUpdate() {
				// 当弹窗显示的时候才强制刷新页面
				if (this.show) {
					this.$forceUpdate()
				}
			},
			//长按事件相关内容---------开始-------------------
			//接触开始
			handletouchstart(e) {
				var tchs = e.touches.length;
				if (tchs != 1) {
					return false;
				}
				this.time = setTimeout(() => {
					this.onLongPress(e);
				}, this.interval);
				return false;
			},
			//清除定时器
			handletouchend() {
				clearTimeout(this.time);
				if (this.time != 0) {
					//处理点击时间
				}
				return false;
			},
			//清除定时器
			handletouchmove() {
				clearTimeout(this.time);
				this.time = 0;
			},
			// 处理长按事件
			onLongPress(e) {
				var src = e.currentTarget.dataset.src;
				var index = e.currentTarget.dataset.index;
				var data = {
					src: src,
					index: index
				};
				this.$emit('longPress', data);
			},
			//长按事件相关内容---------结束-------------------

			//图片改变
			swiperChange(e) {
				this.index = e.target.current; //更新当前图片index

				this.$nextTick(function() {
					this.scale = 1;
				})

				//this.deg = 0; //旋转角度
				//this.swiper=true;
			},

			//移动变化
			movableChange(e) {
				//console.log(e);
				/* if(this.old.scale <= 1){
					this.swiper=false;
				}else if(e.detail.x===0){
					this.swiper=false;
				} */
			},
			// 编辑
			edit(i) {
				this.$emit('edit', i)
			},
			// 删除
			del(i) {
				this.$emit('del', i)
			},

			//保存
			save(e) {
				var _this = this;
				var src = this.imgs[this.index];
				//#ifdef MP-WEIXIN
				//提前向用户发起授权请求
				uni.authorize({
					scope: 'scope.writePhotosAlbum',
					success() {
						console.log('kxj-previewImage:允许储存');
						_this.downloadImg(src);
					}
				});
				//#endif

				//#ifdef APP-PLUS
				this.downloadImg(src);
				//#endif

				//#ifdef H5
				//非同源图片将直接打开
				var abtn = document.createElement('a');
				abtn.href = src;
				abtn.download = '';
				abtn.target = '_blank';
				abtn.click();
				//#endif
			},

			//下载并保存文件
			downloadImg(src) {
				//下载图片文件
				uni.showLoading({
					title: '大图提取中'
				});
				uni.downloadFile({
					url: src,
					success: function(res) {
						console.log('kxj-previewImage:下载成功');
						uni.hideLoading();
						uni.saveImageToPhotosAlbum({
							filePath: res.tempFilePath,
							success: () => {
								uni.showToast({
									title: '已保存至相册',
									duration: 1000
								});
							}
						});
					},
					fail: function() {
						uni.hideLoading();
						uni.showToast({
							title: '图片下载失败',
							icon: 'none',
							duration: 1000
						});
					}
				});
			},

			//旋转
			rotate(e) {
				this.deg = this.deg == 270 ? 0 : this.deg + 90;
			},
			//打开
			open(e) {
				if (e === null || e === '') {
					console.log('kxj-previewImage:打开参数无效');
					return;
				}

				if (!isNaN(e)) {
					if (e >= this.imgs.length) {
						console.log('kxj-previewImage:打开参数无效');
					} else {
						this.index = e;
					}
				} else {
					var index = this.imgs.indexOf(e);
					if (index === -1) {
						this.imgs = [e];
						this.index = 0;
						console.log('kxj-previewImage:未在图片地址数组中找到传入的图片，已为你自动打开单张预览模式')
					} else {
						this.index = this.imgs.indexOf(e);
					}
				}
				// console.log('kxj-previewImage:当前预览图片序号' + this.index);
				this.show = true;
			},
			//关闭
			close(e) {
				this.show = false;
				this.index = 0; //当前页
				this.deg = 0; //旋转角度
				this.time = 0; //定时器
				this.interval = 1000; //长按事件
				this.scale = 1; //缩放比例
			}
		}
	};
</script>

<!--使用scss,只在本组件生效-->
<style lang="scss" scoped>
	.previewImage {
		z-index: 999999;
		position: fixed;
		top: 0;
		left: 0;
		width: 100%;
		height: 100%;
		background-color: #000000;
		user-select: none;

		.swiper {
			width: 100%;
			height: 100%;

			.marea {
				height: 100%;
				width: 100%;
				position: fixed;
				overflow: hidden;

				.mview {
					display: flex;
					align-items: center;
					justify-content: center;
					width: 100%;
					height: auto;
					min-height: 100%;

					.image {
						width: 100%;
					}
				}
			}
		}

		.page {
			position: absolute;
			width: 100%;
			bottom: 20rpx;
			text-align: center;

			.text {
				color: #fff;
				font-size: 26rpx;
				background-color: rgba(0, 0, 0, 0.5);
				padding: 3rpx 16rpx;
				border-radius: 20rpx;
				user-select: none;
			}
		}

		.save {
			position: absolute;
			// left: 10rpx;
			width: 140rpx;
			height: 56rpx;
			bottom: 10rpx;
			text-align: center;
			padding: 10rpx;

			&.edit {
				top: 50rpx;
			}

			&.del {
				right: 10rpx !important;
				top: 50rpx;
			}

			.text {
				background-color: rgba(0, 0, 0, 0.5);
				color: #fff;
				font-size: 30rpx;
				border-radius: 20rpx;
				border: 1rpx solid #f1f1f1;
				padding: 6rpx 22rpx;
				user-select: none;
			}

			.text:active {
				background-color: rgba(100, 100, 100, 0.5);
			}
		}

		.rotate {
			position: absolute;
			right: 10rpx;
			width: 140rpx;
			height: 56rpx;
			bottom: 10rpx;
			text-align: center;
			padding: 10rpx;

			.text {
				background-color: rgba(0, 0, 0, 0.5);
				color: #fff;
				font-size: 30rpx;
				border-radius: 20rpx;
				border: 1rpx solid #f1f1f1;
				padding: 6rpx 22rpx;
				user-select: none;
			}

			.text:active {
				background-color: rgba(100, 100, 100, 0.5);
			}
		}

		.desc {
			position: absolute;
			top: 0;
			width: 100%;
			padding: 5rpx 10rpx;
			text-align: center;
			overflow: hidden;
			text-overflow: ellipsis;
			white-space: nowrap;
			background-color: rgba(0, 0, 0, 0.5);
			color: #fff;
			font-size: 28rpx;
			letter-spacing: 3rpx;
			user-select: none;
		}
	}
</style>
